U.S. farmers export a large amount of hay products to foreign countries each year. The hay is harvested, baled, and then placed in large shipping containers for transfer to foreign countries. To reduce freight costs, it has become a practice within the industry to press hay into small units of higher density so that more hay can be placed within each container. For example, field-baled hay bales are compressed one-third to one-half their original size.
Conventional hay bale recompression systems include a press and a banding machine (or alternately, a twine knotter). The press has a chamber into which a normal-sized hay bale is transferred by an input hydraulic cylinder or ram. Such a hay bale is typically referred to as a "charge of hay". Once inside the chamber, a compression hydraulic ram compacts the hay bale. Thereafter, an output hydraulic cylinder forces the bale from the compression chamber into a strapping chamber at the banding machine.
Conventional banding machines employ four rectangular tracks which surround the strapping chamber. The strapping chamber has peripheral slots that enable the bands or straps to be pulled into the chamber and bound around the hay bales. The bales are indexed to place two sets of straps thereon. The straps maintain the integrity and form of the compressed hay bale.
The bound bales can then be pushed from the banding machine to a cutting unit having a knife or blade which is passed vertically through the bale to sever it into two uniform size and weight bales suitable for handling and shipping. If cut, the two sets of bands are divided such that one set of bands retains the shape of one of the resulting bales, while the second set of bands retains the shape of the other bale. If a large bale is desired, the bale remains uncut. A full bale weighs approximately 150 pounds and a severed baled forms two 75 pound bales. The bales are then placed in shipping containers for export to foreign countries.
Hay bale recompression systems of the type described above are disclosed in U.S. Pat. No. 5,001,974 to Gombos and U.S. Pat. Nos. 4,676,153, 4,718,335, and 4,763,574 to Ast.
Conventional hay bale recompression systems have a significant drawback stemming from the use of the banding machine. Employment of the banding machine introduces inefficiency into the system because the hay bales periodically stop for intervals of 3-5 seconds so that the straps can be placed on them. Because two sets of straps are placed on each bale, the entire system is forced to stop for an interval of 6-10 seconds simply due to the banding apparatus.
Another drawback is that the hay bales must be precisely indexed and positioned within the banding machine so that both sets of bands are not applied in a skewed or off-center manner relative to the bale. If the hay bale is not precisely positioned, the bands may be longitudinally displaced a sufficient amount that, after the bales have been severed at the cutting station, one or more of the bands slip off causing the hay bale to fall apart.
Another problem associated with the banding machine is that it contributes a significant portion of the overall system downtime due to breakdown or cleaning. The banding machine is a relatively delicate instrument as the tracks must be kept clean and the strap guides maintained to insure proper operation.
Another drawback associated with conventional bale recompression systems concerns the resulting bale product. Conventional systems produce a compact hay bale having a set of straps bound around it to hold the bale together. However, the straps are very narrow and often do an inadequate job of holding the hay together as a bale. During transport, portions of the hay bale may be disconnected from the bale and lost, thereby resulting in an inefficient transport of the hay.
Another drawback is that the resulting bale product must be individually carried and placed on a shipping pallet or in the shipping container for export. This is an inefficient and labor-intensive approach to filling the shipping container. U.S. Pat. No. 5,111,931 discloses a technique in which multiple hay bales are arranged in rows and columns, and then bound together as a unit by a sheet of pre-stretched polymeric film to create a "pallet"-size bundle that can be handled by a forklift truck or the like. However, the process in the '931 patent requires that each hay bale within the "pallet"-size bundle be individually banded prior to being wrapped with the film, and thus the problems associated with banding remain. Additionally, each bound bale must be carried and placed in a preset pattern with other bales before the wrap is applied.
U.S. Pat. No. 5,012,631 discloses a portable bale wrapping machine for wrapping a protective plastic film around large bale rolls to protect the bales from weather during outdoor storage. However, the plastic film is applied only to bales of hay that have already been banded with straps. The plastic film is merely for protection from the weather, and is not used to maintain the integrity of the rolled hay bale. Accordingly, the bale wrapper in the '631 patent has the drawback in that the bales of hay must first be banded prior to application of the protective plastic film.
This invention eliminates the above-identified problems of conventional systems by providing a system and method for packaging bales of hay.